implies that ‘Dunefolk’ is a quality present or applied to a subset of the other. I.e. that the Dunefolk are an offshoot from the greater human genus.
However, “Dunefolk humans” sounds very uncouth: Is Dunefolk a collective identity or an adjective appellation? Can there be Dunefolk Orcs? Dunefolk are Dunefolk. If anything,

Dunefolkian humans

Of course, bear in mind that I prefer to use ‘human’ as an adjective and not a noun. I did not in the above examples, but something like that could affect my interpretation.

I thought the description was purposely vague as a way of generating consensus among everyone, and to leave things open for campaigns to explore.

It was, but in this case all the units are already shown as Dunefolk Human on the right side-panel, so it's really just a question of if they should be explicitly mentioned as being Human in the race description as well or not, and if so then how.

99 little bugs in the code, 99 little bugs
take one down, patch it around
-2,147,483,648 little bugs in the code

It was, but in this case all the units are already shown as Dunefolk Human on the right side-panel, so it's really just a question of if they should be explicitly mentioned as being Human in the race description as well or not, and if so then how.

This is exactly my point. It is given for certain that they are humans by the Dunefolk Human label in the side-panel (and by the outcome of this long thread). My view is that it should be mentioned also in the description, and it is enough to add a single word. I like the saying "Dunefolk humans" the most because this is coherent with the side-panel and because this clearly says that they are a subset of the humans who belong to the people of the dunes, while there are other humans who are the Wesnoth humans, the Wesfolk humans, and so on.

Just dunefolk seems fine to me. adding human at the end seems.. off and brings a variety of questions to mind. It's not like anyone would think they r non human when they look upon dunefolk units for the first time. they seem pretty grounded in reality to me.(for a fantasy setting as wesnoth)

It is the mark of an educated mind to be able to entertain a thought without accepting it.
Playing Wesnoth since 2010, still there is so much left to play

"Speaking of which, I thought of a lore for the reason why Dunefolk live in the dunes, don't weild magic, and are vulnerable to impact and resistant to pierce!

It is because their armor is made of an alloy from a metal unique to their homeland. Khalcium sand (hehe see what I did there?) can be mined underneath the dunes of their homes and the deposits are one of the primary reasons why the various Dunefolk tribes war with each other. Khalcium has the peculiar property of being able to efficiently distribute localized force inside itself (hence pierce resist). However should the force be simultaneously applied in a wide area (i.e. impact) the redistribution causes the build up of force in the center of the area sometimes creating splinters / shrapnel. But what makes armor / clothes / buildings laced with it so ubiquitous with the Dunefolk is its ability to dissipate desert radiant heat extremely well (but making wearers vulnerable to cold based attacks); it is also a key metal used in the creation of naptha by the secretive Naptha Guilds, and the science of the Alchemy guilds.

What makes Khalcium truly precious though and why it is the one of the major trade exports of the Sandy Wastes (?) is its effect on the magical, capable of disrupting all manner of ethereal energies. This anti-magic effect of the metal is why it is very rare that a mage emerges from the Dunefolk; not for lack of skill, but rather their culture and technology is so permeated with it that the talent is seldom even discovered, much less cultivated. Eventually this evolved in the Dunefolk an active disdain, skepticism and avoidance of magic, something they don't use much in daily life anyway.

So why is this relevant in the balance thread you ask? Well:

This combination of point force redistribution and anti-magic is harnessed by the elite cavalry of the Dunefolk people. Forging powerful alloy lances from the metal, those called Dune Pierces ravage the enemy lines with their famed Khalcified lances.

20-1 Arcane damage. (we adjust this based on Rebel and Undead balance, perhaps increase cold vulnerability to 30%, but at its cost I doubt its needed.)

We can nerf Naptha melee by 1 or 2 points to help balance the Rebel match up.

BOOM! Niche made!"

This is a good opportunity since we're revisiting the unit descriptions anyway. What do you guys think?

P.S. "Millions of years ago a meteorite made of khalcium, the most peculiar substance in the universe, struck the continent of Wesnoth, creating a desert and affecting the dunes around it. And when the time of men came, the tribes settled on it and called it Wakanda."

P.P.S. If the balance changes don't push through, it could be a proposed past for the Dune folk, with the kind of Khalcium used for the Khalcified lances becoming increasingly more rare (hence Khalcified lances are rare heirlooms seldom used in combat now). It could still explain their cultural attitude to magic even if the homes / armor now have lower concentration of Khalcium metal, using an inferior alloy.

P.P.P.P.S. Incidentally, this also provides the perfect explenation for liminal. Not only is it culturally the most comfortable time during the desert day; it also is the optimum temperature for khalcium thread clothing. At full day, the khalcium expends its energies dissipating heat, while at late night the wearer is negatively affected by the cold.